The objective of these studies is to determine the biochemical changes in the mouse uterus under conditions mimicking those of early pregnancy. The effect of the decidualizing stimulus, as well as the effects of the prior hormonal treatment with estradiol and progesterone, on a number of biochemical parameters is to be studied. Particular attention will be paid to changes in RNA and protein synthesis and to changes in the levels of factors known to influence the synthesis of these macromolecules. Include among the latter will be cyclic nucleotides, prostaglandins and polyamines. In turn, the enzymes known to influence levels of these metabolic regulators will be investigated. Included in the immediate plans are studies of levels of nucleotide cyclases, cyclic nucleotide phosphodiesterases and ornithine decarboxylases. Studies on the rates of protein and nucleic acid synthesis are planned as are studies on the qualitative patterns of these macromolecules. BIBLIOGRAPHIC REFERENCES: Cyclic nucleotide levels in the mouse uterus during artificially stimulated decidualization. B. E. Ledford, J. C. Rankin and B. Baggett, Fed. Proceedings 34, 695 (1975). (abstract).